The objective of this proposal is to design and fabricate a breath activated medication spray (BAMS) dispenser. The device will be fully tested for loading the canister; optimization of the specifications of the main spring; ease of setting the trigger; repeat reliability of the trigger mechanisms; optimization of the battery holder for ease of replacement and economy of space; optimization of discharge oriface for correct particle size; provisions for adaptation for various sizes and shapes of canisters; adjustment of the trigger for different breath cycles and inspiratory times; theoretical considerations of the dispersal of the aerosol particles from the site of delivery to the lung alveoli; the effects of position of the device on flow rates and activation of switch; laboratory testing to demonstrate the BAMS device will work satisfactorily with all commonly available metered dose inhallers; durability of the device, including the number of cycles to be expected from the mechanism and the resistance to mechanical shock; complete understanding and description of the operation, assembly and safety aspects of the device. Upon successful completion of these elements, a limited field trial will be performed to test the effectiveness of the BAMS device and to evaluate its effectiveness compared to the traditional metered dose inhalers, in the delivery of therapeutic aerosols to subjects suffering from chronic and acute respiratory diseases.